The present research proposal is designed to investigate potential mechanisms that may explain why work in adolescence is associated with an increased risk of drug involvement. Although much research has shown associations between work intensity and work quality on drug involvement, very little research has been performed that has investigated the mechanisms that explain why adolescents who work are at greater risk for drug involvement. The mechanisms that will be investigated are: (1) work intensity and poor work quality in adolescence are features of a developmental pathway, termed precocious development, that is also associated with adolescent drug involvement; (2) through work, adolescents are exposed to more opportunities to initiate drug use which is associated with drug involvement; (3) working generates income that adolescents use to procure drugs. Each mechanism will be investigated as acting independently as well as in conjunction with the other theories presented. Data from a prospective, longitudinal study of 678 adolescents in an urban setting, interviewed annually for ten years beginning in the first grade, will be used to investigate these issues.